• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.100-105
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• 2016

The use of 3D scanners has increased gradually according to increasing 3D printer applications. The precision inspection of car parts or electronic components is an important issue not only in the field of mass production, but also in small-scale production. Recently, 3D scanner equipment efficiency and recognition technology has been improved continuously. On the other hand, the spraying time to prepare 3D scanning is time-consuming and has environmental problems. Therefore, an automatic spray system has been in demand by the manufacturing industry. Automatic spray equipment was newly developed for the preparation of a 3D scanner. In this research, the automatic spray system guarantees uniform spray operation. To determine the optimal spray parameters, various spraying methods, solutions and conditions were tested and compared with the experiments. The preparation time for 3D scanning was reduced to 1/10 compared to the manual spraying time, and indicates the optimal spraying conditions through a comparison of various spray coating conditions.

• Journal of dental hygiene science
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• v.15 no.1
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• pp.54-59
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• 2015

The present study investigated the influences of various abutment teeth shapes (maxillary right canine, pre-molar, molar) on the marginal adaptation of computer aided design/computer aided manufacturing-fabricated zirconia core. In vitro adaptation of zirconia cores manufactured by three different abutments were evaluated. Thirty zirconia cores were made per each models and the adaptation was evaluated through a silicone replica technique. The measurement of the adaptation was carried out using digital microscope. The mean and standard deviation of each reference point were analyzed using the one-way (ANOVA) and Tukey's honestly significant difference tests (${\alpha}=0.05$). The overall marginal fits of the zirconia cores were as follows: canine: $47.59{\mu}m$, pre-molar: $43.74{\mu}m$, molar: $40.36{\mu}m$. They were no statistically significant differences between groups for adaptation (p>0.05). This confirmed that the type of abutment teeth used does not determine the precision of fit of zirconia core.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.77-87
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• 2004

It is important for hydrographers to extract the accurate cross section of a river for the hydrographical analysis of the topography. Aerial photographs were used to extract the cross section of a river for the advantages of the accuracy and economical efficiency in this study, while the direct measurement has been used in existing studies. An ortho-rectified photo map using imageries taken by the PKNU 2 (High-resolution, multi-spectral, aerial photographic system developed by our laboratory) was generated using the surveyed data and a digital map. The cross section of a river that was obtained from the ortho-rectified by the surveyed Kinematic data of GPS was compared with the result using ImageStation stereo-plotter of corp. Z/I Imaging. As a result of this study, the RMSE in the ortho-rect process using the surveyed GPS data was lowered as from 5.5788 pixels (about 2m) to 2.84 (about 1m) in comparison with it in the process using a digital map. The surveyed kinematic GPS in extraction of the cross section of a river was excellent as 6.6cm of the planimetric and precision in the confidence level of 95%. The correlation coefficient between the result from the using stereo-plotter and the extraction of cross section of a river using aerial photos was 0.8 hydrographical acquisition of it using PKNU 2 imagery will be possible.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.139-144
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• 2012

The purpose of this study was to evaluate the accuracy and reproducibility of measuring the size of unerupted permanent tooth via cone beam computed tomography(CBCT). Ten children were scanned with dental CBCT, and 3-dimensional reconstruction of the dentitions were generated CBCT. Mesio-distal dimension and buccolingual dimension of the teeth were made directly on the model with a high-precision digitalcaliper and on the CBCT by using three-dimensional dental imaging software. Reliability and accuracy were assessed by using intraclass correlation and paired $t$-tests. ($p$ <0.05) The results were as follows : 1. Intraclass correlations were above 0.9 for Both the CBCT and the model measurements, showinghigh reliability. 2. Although there were high correlation values(r=0.91) between CBCT and model messurement methods, comparisons between the CBCT and model messurement methods showed a statistically significant difference($p$ <0.05). 3. The CBCT measurements tended to slightly underestimate by 0.2 mm. But, the systematic difference of CBCT measurements were clinically acceptable Therefore, CBCT measurement method can be used to measure the size of unerupted teeth in a sufficiently accurate way.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.73-80
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• 2010

This study was conducted to estimate the relative performance of modules with changed characteristics due to long term exposure to the outdoor environment, with a specially made test device for simultaneous measurement of real time power output from the photovoltaic array, taking into account the inclined panel, direct irradiation, power being generated, temperature as well as the optimal analysis timing. In terminology description, M is an abbreviation of module and Group A, Group B are 10 modules series connection (1~10 of M), (11~20 of M) for each of them respectively. The overall mean voltage difference of M-18 with the lowest power output and M-14 with the highest output is-2.13V and it was identifiable that voltage difference was more concentrated to Group B. In addition, in case of M-2 and M-7, M-8, when compared with M-14, the overall mean voltage difference was -0.92V, -1.56 and -0.91V respectively showing the more concentration to Group A. When the temperature of module went up by $1^{\circ}C$, the mean voltage was reduced by 0.35V. For current, Group A was lower than Group B by-0.022A and the ratio of each group was 49.68% and 50.32% respectively, presumably the module with deteriorated properties were more concentrated to Group A relatively. From the comparison of relations with the comprehensive accumulation, M-2, M-7, M-8, M-16 and M-18 were those with deterioration of performance to the worst, thereby requiring precision examination. In comparative efficiency, M-14 was the most excellent one as 12.19% while M-18 as 10.53% was identified that its efficiency was comparatively rapidly reduced.

• Journal of IKEEE
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• v.21 no.4
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• pp.368-374
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• 2017

In this Paper, we developed a low power type LED security light using LED lighting that substitutes a 220[V] commercial power source for a solar cell module instead of a halogen or a sodium lamp. in addition, a PWM type drive control circuit is designed to minimize the heat generation problem and the drive current of the LED drive controller. in developed system, The light efficiency measurement value is 93.6[lm/W], and a high precision temperature sensor is used inside the controller to control the heat generation of the LED lamp. In order to eliminate the high heat generated from the LED lamp, it is designed to disperse quickly into the atmosphere through the metal insertion type heat sink. The heat control range of LED lighting was $50-55[^{\circ}C]$. The luminous flux and the lighting speed of the LED security lamp were 0.5[s], and the beam diffusion angle of the LED lamp was about $110[^{\circ}C]$ by the light distribution curve based on the height of 6[m].

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.2
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• pp.165-173
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• 2006

Purpose: With gold electroforming system fir the double crown, the secondary crown is electroformed directly onto the primary crown. An even thick layer of high precision can be acquired. It is thought that the retention of electroformed outer crown is primarily acquired by the adhesive force (surface tension) through the saliva which is interposed between precisely fitted inner and outer crown. The purpose of this study was to investigate the effect of taper and surface area of inner crown on the retentive force of electroformed outer crown according to the presence of saliva. Materials and methods: 32 titanium inner crowns with cervical diameter of 8 mm and cone angles of 0, 2, 4, 6 degrees, which had same surface area by regulated height, were machined on a lathe. Another 32 titanium inner crowns with cone angles of 0, 2, 4, 6 degrees, which had doubled surface area by increased cervical diameter. were fabricated. Eight specimens of each group, for a total of 64 titanium inner crowns, were prepared. The electroformed outer crowns were fabricated directly on the inner crowns by using electroforming machine(GAMMAT free, Gramm Technik, Germany). The tertiary frameworks were waxed-up on the electroformed outer crown and cast using nonprecious alloy($Rexillium^(R)III,\;Jeneric^(R)/Pentronh^(R)$ Inc., USA). The cast metal frameworks were sandblasted with alubimium oxides and cemented using resin cement(Superbond C&B, Sun Medical Co., Japan) over the electroformed copings of each specimen. Then, artificial saliva($Taliva^(R)$, Halim Pharm. Co., Korea) was sprayed between the inner and outer crown, and they were connected under 5 kg force. The retentive force was measured by the universal testing machine(Tinius Olsen 1000, Tinius Olsen, USA) with a cross-head speed of 66.67 mm/sec. The direction of cross-head travel was exactly aligned with the path of removal of the respective specimens. This measurement procedures for retentive force of electroformed outer crown with artificial saliva were repeated in the same way without presence of artificial saliva. Results and Conclusion: The following conclusions were drawn: 1. The retentive force of electroformed outer crown was decreased according to increased taper of inner crown(P<.05). 2. The retentive force of electroformed outer crown showed no significant differences according to surface area and the presence of artificial saliva(P>.05).

• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.134-139
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• 2011

In this research, we developed the newly cloud chamber apparatus by using Peltier device to apply nuclear physics experiment in high school or university. We observed the cosmic rays track by using the developed apparatus and a camcorder. And we compared and analyzed the acquired data. From the results, we acquired the following conclusions and suggestions : First, it is very difficult to observe the cosmic rays track in the typical cloud chamber because of the low frequency of it. But in the newly developed cloud chamber we can observe easily the cosmic rays track owing to the high frequency of it. Second, when we do the experiment with the newly developed apparatus, we found that the cosmic rays track happens well under the condition that the temperature of the upper place of cooling plate must be below 5$^{\circ}C$ with more than isopropanol $1.04{\times}10^{-5}$ $ml{\cdot}mm^{-3}$. Third, the newly developed apparatus will be improved to have better precision by controling the temperature of cooling plate in the cloud chamber by current intensity. Therefore we think that it is very useful to use the newly developed apparatus in the nuclear physics experiment in highschool or university.

• Korean Journal of Optics and Photonics
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• v.4 no.1
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• pp.15-21
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• 1993

This paper describes the design and development of a KrF excimer laser stepper and discusses the detailed system parameters and characterization data obtained from the performance test. We have developed a deep UV step-and-repeat system, operating at 248 nm, by retrofitting a commercial modules such as KrF excimer laser, precision wafer stage and fused silica illumination and 5X projection optics of numerical aperture 0.42. What we have developed, to the basic structure, are wafer alignment optics, reticle alignment system, autofocusing/leveling mechanisms and environment chamber. Finally, all these subsystem were integrated under the control of microprocessor-based controllers and computer. The wafer alignment system comprises the OFF-AXIS and the TTL alignment. The OFF-AXIS alignment system was realized with two kinds of optics. One is the magnification system with the image processing technique and the other is He-Ne laser diffraction type system using the alignment grating on the wafer. 'The TTL alignment system employs a dual beam inteferometric method, which takes advantages of higher diffraction efficiency compared with other TTL type alignment systems. As the results, alignment accuracy for OFF-AXIS and TTL alignment system were obtained within 0.1 $\mu\textrm{m}$/ 3 $\sigma$ for the various substrate on the wafers. The wafer focusing and leveling system is modified version of the conventional systems using position sensitive detectors (PSD). This type of detection method showed focusing and leveling accuracies of about $\pm$ 0.1 $\mu\textrm{m}$ and $\pm$ 0.5 arcsec, respectively. From the CD measurement, we obtained 0.4 $\mu\textrm{m}$ resolution features over the full field with routine use, and 0.3 $\mu\textrm{m}$ resolution was attainable under more strict conditions.

• YAKHAK HOEJI
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• v.51 no.2
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• pp.96-102
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• 2007

Measurement of globotriaosylceramide (Gb3, ceramide trihexoside) in urine has clinical importance for monitoring after enzyme replacement therapy in Fabry disease patients. The disease is an X-linked lipid storage disorder that results from a deficiency of the enzyme ${\alpha}$-galactosidase A (${\alpha}$-Gal A). The lack of ${\alpha}$-Gal A causes an intracellular accumulation of glycosphingolipids, mainly Gb3. A simple, rapid, and highly sensitive analytical method for Gb3 in urine was developed without labor-extensive pre-treatment by electrospray ionization MS/MS (ESI-MS/MS). Only simple 5-fold dilution of urine is necessary for the extraction and isolation of Gb3 in urine. Gb3 in diluted urine was dissolved in dioxane containing C17:0 Gb3 as an internal standard. After centrifugation it was directly injected and analyzed through guard column by in combination with multiple reaction monitoring mode of ESI-MS/MS. Eight isoforms of Gb3 were completely resolved from urine matrix. C24:0 Gb3 occupied 50% of total Gb3 as a major component in urine. Linear relationship for Gb3 isoforms was found in the range of 0.005${\sim}$5.0 ${\mu}$g/ml. The limit of detection (S/N=5) was 0.005 ${\mu}$g/ml and limit of quantification was 0.05 ${\mu}$g/ml for C24:0 Gb3 with acceptable precision and accuracy. Correlation coefficient of calibration curves for 8 Gb3 isoforms ranged from 0.9598 to 0.9975. This method could be useful for rapid and sensitive 1st line Fabry disease screening, monitoring and/or diagnostic tool for Fabry disease.